The invention is directed to a lubrication pump with a stroking action of a delivery piston with regulatable metering of the amount of lubricant delivered with each stroke of the pump, wherein the delivery piston actuated by the pump aspirates or sucks the lubricant into a suction space whose volume is adjustable, wherein furthermore the lubricant is fed from the suction space through an intermediate storage space to the lubricant outlet or to the lubrication circulation circuit and wherein a check valve is provided in the above-mentioned path of the lubricant. More particularly, the present invention relates to lubrication pumps for central lubrication systems of utility vehicles, including trailers, semi-trailers, special vehicles, and the like. The lubricant can be of different types, including lubricants with very high penetration which are difficult to squeeze out. In such a lubrication pump the check valve, viewed in the conveyance direction of the lubricant has previously been provided following upon an intermediate receiving space directly upstream of the outlets to the lubricant's circulation circuit or the lubrication lines of the system which is to be lubricated. Herein it has proved disadvantageous that a mixture of lubricant and air is formed in the intermediate receiving space.
This again entails that during a stroke of the delivery piston the air portion of the mixture present in the intermediate receiving space was compressed so that the quantity of lubricant provided by the adjustment of the arrangement was not fed to the appropriate point to be lubricated, rather only a fraction thereof. The deviation of the lubricant actually fed to the lubrication circulation circuit from the adjusted quantity of lubricant became correspondingly greater, the smaller the quantity of lubricant adjusted by means of the actuation arrangement.
The aim of such a lubrication pump, namely a sufficiently accurate adjustment of the quantity of lubricant to be fed to the lubrication circulation circuit with each stroke of the delivery piston was thus not achieved at all, or at best only incompletely.